Several methods have been attempted to manufacture a non-impact printer-compatible mailer-type of business form with a top-opening return envelope. The concept heretofore used has been to create a two-part web, containing a wide and a narrow sheet, heat seal spot pasted on the removal stub areas, and pocket pasted to create a return envelope. The wide web, part 1, has contained a glassine patch over a die-cut window, thus allowing the outgoing address to appear. The back of the two-part web has contained heat seal adhesive in a full perimeter pattern. Part 2, imaged by a laser or impact printer, has contained stub removal perforations, but no heat seal adhesive.
The problem in manufacturing this product is ensuring proper alignment (.+-.1/64") from part-to-part of the removal perforations. Since these perforations on the two-part web are put on at the collator, and the corresponding perforations for the imaged sheet (i.e. the variably-printed sheet) are put on at the press, two different perforation units are used, and perf alignment has been very difficult to guarantee.
The problem with the heretofore conventional manufacturing method has been to match the perfs (form depth and sub removal) applied on one sheet at press, with the perfs on the two-part pasted set applied at the collator.